Washington -LRB- CNN -RRB- -- Groups representing federal air marshals and flight attendants -- outraged over the Transportation Security Administration 's decision to allow small pocketknives back into aircraft cabins -- say they will ask the TSA to reconsider the policy .

Both groups say they learned about the policy change Tuesday , and charged that the TSA is forgetting about the terrorist attacks that led to the formation of the agency .

`` It 's as if we did n't learn anything from 9/11 , '' said George Randall Taylor , head of the air marshal unit of the Federal Law Enforcement Officers Association -LRB- FLEOA -RRB- . `` Flight attendants are going to be sitting ducks . ''

On Tuesday , TSA Administrator John Pistole announced that small pocketknives and an array of sporting equipment -- which were banned from aircraft cabins in the wake of the 9/11 terrorist attacks -- will be allowed in U.S. planes beginning April 25 .

Former TSA chief backs ` knife ' decision ; suggests axes and machetes , too

Pocketknives will be allowed if the blade is no longer than 2.36 inches -LRB- 6 centimeters -RRB- , which is shorter than the 4-inch blades that were allowed at the time of the 2001 attacks . And they must adhere to other rules : the blade can be no more than 1/2 inch at its widest point , it can not have a locking or fixed blade and can not have a molded grip . Box cutters and razor blades are still not allowed inside the passenger cabin .

The TSA also will allow travelers to bring billiard cues , ski poles , hockey and lacrosse sticks and a maximum of two golf clubs into aircraft cabins as carry-on baggage . It will allow novelty and toy bats if they measure less than 24 inches and plastic bats if they weigh less than 24 ounces .

Some experts say security improvements since the attacks -- most notably reinforced cockpit doors , better intelligence and motivated passengers -- have made the strict prohibition of small pen-knives unnecessary .

But Taylor said he is `` appalled '' by the decision , and said air marshals are voicing their opposition to him . `` I 've received probably over a hundred -LRB- calls from air marshals -RRB- . They 're very upset . ''

FLEOA President Jon Adler said the dangers extend beyond air marshals . `` Pistole 's decision is putting my guys at greater risk , '' Adler said . `` It 's not just the -LRB- Federal Air Marshal Service -RRB- , it 's all of my guys , '' he said , noting that law enforcement officers are allowed to carry weapons during commercial flights .

A union representing 90,000 flight attendants called the measure `` a poor and short-sighted decision by the TSA . ''

`` Continued prohibition of these items is an integral layer in making our aviation system secure and must remain in place , '' the Coalition of Flight Attendant Unions said in a statement .

Pistole said the TSA sought to distinguish small pocketknives , such as those equipped with corkscrews , from sturdier knives used primarily as weapons . Screeners seize on average 47 of the smaller knives every day from Los Angeles International Airport alone , he said Tuesday .

Opinion : Is TSA serious about letting people carry knives ?

The new rule will allow screeners to focus on finding explosive device components and other things that can be `` catastrophic '' to a plane , speed trips through security checkpoints and `` address the hassle factor , '' Pistole said .

Pistole said his agency consulted with its federal air marshals and other experts before making the change , and that led to the continued prohibition of the sturdier knifes with short blades .

`` Experts in martial arts and close-quarters combat talked passionately about some of these smaller -LRB- knives -RRB- , even though they 're smaller than 6 centimeters . Some of these knives are primarily weapons and do not serve the similar purpose as what you would call a small pocketknife . Some are for hunters , for skinning ; some are simply for weapons . And so those will still remain on the prohibited items list , '' Pistole said .

Box cutters are prohibited regardless of blade length , he said .

`` I wish -LRB- the new rule -RRB- could be as clean as possible , '' Pistole said . But `` there 's just too much emotion associated with particularly the box cutters , so those will not be allowed . ''

Although it was widely reported that the 9/11 hijackers used box cutters in their attack , the weapons were not recovered , and investigators believe other types of knives were used .

`` Our best working hypothesis is that a number of the hijackers were carrying -- permissible under the regulations in place at the time -- permissible utility knives or pocket knives , '' a commission staff member said at a January 2004 hearing of the 9/11 Commission .

A Leatherman knife was displayed during the hearing . The commission said its investigation found that `` at least two knives like this were actually purchased by the hijackers and have not been found in the belongings the hijackers left behind . ''

Immediately after the attacks , the TSA prohibited a wide range of items from aircraft cabins . But it has gradually been reintroducing some banned items such as cigarette lighters and matches . On occasion the TSA has expanded the list , as it did after a liquid bomb scare in August 2006 when it prohibited bringing large containers of liquids and gels on board aircraft .

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TSA chief explains factors that went into decision

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Law enforcement officers ' group will ask the TSA to reconsider

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The changes will allow small knives and some sports equipment in cabins

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A flight attendant union calls it a `` short-sighted '' decision